Biology subjects

Slaby, E. M.

Publications and source records attributed to Slaby, E. M..

4 recordsLinked to original sources

bioRxiv2024

Human placental organoids as a model to probe early gestation maternal immune dynamics

During pregnancy, the human placenta establishes tolerance toward fetal allogeneic tissue, where specialized trophoblast subtypes play a complex role in local and peripheral immunomodulation. However, due to inadequate models to study the early gestation of the human placenta, each trophoblast subtypes role in modulating the maternal immune response has remained elusive. Here, we derived human placental organoids from early gestation trophoblast stem cells to (1) identify patterns of immunomodulatory protein expression by trophoblast subtype and (2) evaluate the effects of the placental organoid secretome on immune cell activation and regulation. We show that the three primary trophoblast phenotypes had distinct influences on immune cell phenotype and activation and that three-dimensional culture significantly alters trophoblast immunomodulation relative to traditional two-dimensional trophoblast culture.

bioengineering↗

bioRxiv2022

Lipid-polymer hybrid nanoparticles utilize B cells and dendritic cells to elicit distinct antigen-specific CD4+ and CD8+ T cell responses

Antigen presenting cells (APCs) have been extensively studied for treating cancers and autoimmune diseases. Dendritic cells (DCs) are potent APCs that uptake and present antigens (Ags) to activate immunity or tolerance. Despite their active use in cellular immunotherapies, DCs face several challenges that hinder clinical translation, such as inability to control Ag dosing for tuning immune responses and low abundance in peripheral blood. B cells are a potential alternative to DCs, but their poor non-specific Ag uptake capabilities compromise controllable priming of T cells. We developed phospholipid-conjugated Ags (L-Ags) and lipid-polymer hybrid nanoparticles (L/P-Ag NPs) as Ag delivery platforms to expand the range of accessible APCs for use in priming CD4+ and CD8+ T cells. These delivery platforms were evaluated using DCs, CD40-activated B cells, and resting B cells as a diverse set of APCs to understand the impact of various Ag delivery mechanisms for generation of Ag-specific T cell responses. L-Ag delivery (termed depoting) of MHC class I and II-restricted Ags successfully loaded all APC types in a tunable manner and primed both Ag-specific CD8+ and CD4+ T cells, respectively. Incorporating L-Ags and polymer-conjugated Ags (P-Ag) into NPs can direct Ags to different uptake pathways to engineer the dynamics of presentation and shape T cell responses. DCs were capable of processing and presenting Ag delivered from both L- and P-Ag NPs yet B cells could only utilize Ag delivered from L-Ag NPs. Multivariate analysis of cytokines secreted from APC:T cell co-cultures indicated that L-Ag NPs primed different T cell responses than P-Ag NPs. Altogether, we show that L-Ags and P-Ags can be rationally paired within a single NP to leverage distinct delivery mechanisms to access multiple Ag processing pathways in two APC types, offering a modular delivery platform for engineering immunotherapies.

bioengineering↗

bioRxiv2021

Hydrogel injection molding to generate complex cell encapsulation geometries

Biofabrication methods capable of generating complex, three-dimensional, cell-laden hydrogel geometries are often challenging technologies to implement in the clinic and scaled manufacturing processes. Hydrogel injection molding capitalizes on the reproducibility, efficiency, and scalability of the injection molding process, and we adapt this technique to biofabrication using a library of natural and synthetic hydrogels with varied crosslinking chemistries and kinetics. We use computational modeling to evaluate hydrogel library fluid dynamics within the injection molds in order to predict molding feasibility and cytocompatibility. We evaluate the reproducibility of hydrogel construct molding and extraction and establish criteria for the selection of hydrogels suitable for injection molding. We demonstrate that hydrogel injection molding is capable of generating complex three-dimensional cell-laden construct geometries using diverse hydrogel materials and that this platform is compatible with primary human islet encapsulation. We envision the application of this technique with primary cells via an off-the-shelf clinical kit that can be implemented at the patient bedside by a clinician or integrated with scaled, high-throughput automated cell manufacturing processes to generate encapsulated cell-based therapeutic products. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=80 SRC="FIGDIR/small/466681v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@fe1363org.highwire.dtl.DTLVardef@aae4c9org.highwire.dtl.DTLVardef@1927abaorg.highwire.dtl.DTLVardef@1b76af7_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2019

Lipid-mediated insertion of Toll-like receptor (TLR) ligands for facile immune cell engineering

Cell-based immunotherapies have tremendous potential to treat many diseases, such as activating immunity in cancer or suppressing it in autoimmune diseases. Most cell-based cancer immunotherapies in the clinic provide adjuvant signals through genetic engineering to enhance T cell functions. However, genetically encoded signals have minimal control over dosing and persist for the life of a cell lineage. These properties make it difficult to balance increasing therapeutic efficacy with reducing toxicities. Here, we demonstrated the potential of phospholipid-coupled ligands as a non-genetic system for immune cell engineering. This system provides simple, controlled, non-genetic adjuvant delivery to immune cells via lipid-mediated insertion into plasma membranes. Lipid-mediated insertion (depoting) successfully delivered Toll-like receptor (TLR) ligands intracellularly and onto cell surfaces of diverse immune cells. These ligands depoted into immune cells in a dose-controlled fashion and did not compete during multiplex pairwise loading. Immune cell activation could be enhanced by autocrine and paracrine mechanisms depending on the biology of the TLR ligand tested. We determined that depoted ligands can functionally persist on plasma membranes for up to four days in naive and activated T cells, enhancing their activation, proliferation, and skewing cytokine secretion. Depoted ligands provide a persistent yet non-permanent adjuvant signal to immune cells that may minimize the intensity and duration of toxicities compared to permanent genetic delivery. Altogether, these findings demonstrate potential for lipid-mediated insertion (depoting) as a universal cell engineering approach with unique, complementary advantages to other cell engineering methods.

immunology↗